Electro-optic materials exhibit optical properties that can be altered by application of an electric field, current, or other electromagnetic fields. The most common of these materials are liquid crystals, electrochromic, and Kerr materials. Changes in the absorption properties of these materials can be utilized to make electronically controllable devices such as electronically controllable eyewear, goggles, visors, and welding masks. An example of these devices are the e-Tint® based ski goggles sold by UVEX® or autodimming filters sold for welding helmets. In the ski goggle product, a switch is used to change the state of the system from clear (unenergized state) to dark (energized state) and vice versa. Welding helmets use a photosensitive cell, such as a photodiode, photoresistor, solar cell, etc. (collectively named photosensor), which causes application of a voltage to the device when there is sufficient light from the welding arc to activate the device and induce a state change in the material. Once the arc is off, the device returns to the unenergized state. Therefore, currently, to our knowledge, there are commercial systems that provide either manual or automatic control of the optical device but not both within the same device.
One desired feature of electronically controllable optical devices is to give the user of such devices control over many functions in a simple fashion while the user is still “wearing” the device. For example, it is desirable to give the operator the ability to change the state of the device from clear to dark (or colored) as well as the ability to change other features of the device, e.g. the ability to switch between manual and automatic modes. Other operational modes can also be controlled, such as: the ability during the automatic operation mode to set the level of light that can cause a state change (i.e. the sensitivity of the photosensor to the ambient light level), the ability to change the color if the device has multiple color modes, the ability to adjust the “darkness” level of the device, and/or the ability to return the system to its original factory setting.
Therefore, there is a need in the art for an electronically controllable optical device that has a control apparatus that can provide multiple-function control over the optical device either in a “blind” fashion (without the need for the operator to see which switch they are activating) or remotely (e.g. via a remote switch that the user can more freely access).